Method of preserving wood.



' HENRY s. Low), or new YORK, N. Y.

METHOD .OF PRESERVING WOOD.-

No Drawing.

sure, and consists in first placing the article to be treated in a vessel, then hermetically sealing the vessel, then subjecting the article to a vacuum, and then introducing. preservative liquid into the vessel in such manner as to continuously or intermittently drench the surface of the article and create a covering film or succession of films of liquid thereon, and meanwhlle lntroduclng air into the vessel and increasing and varying the pressure of such air upon said film, whereby commingled preservative and air are forced together under equal pressure into the pores, voids, interstices and tissues of the article until the article is sufiiciently impregnated, nor is eventually submerged in the accumulated liquid to secure additional impregnation. When theidesired degree of pressure has been reached and the requisite amount of preservative forced into,- and diffused through the article, the inflow of fluid is cut off, and the pressure within the vessel reduced to, or below, atmospheric, and the accumulated liquid in the vessel withdrawn under such reduced pressure. The purpose of first subjecting the article to be treatedto vacuum is to exhaust the air within the tissues so that minimum resistance is offered to the initial inflow of liquid, and thereby a more effective penetration of liquid is secured than would be the case if the air were present as an obstacle. The manner in which I prefer to introduce the liquid into the vessel is in the form of a spray and under such pressure as will atomize or reduce the same to a vapor, so as to bring it into contact with all the surfaces of the article and completely cover the same with a film.

Obviouslythe inflow of liquid as above set forth might submerge the tie before the requisite amount of commingled preservative and air has been forced into the tie, in which case submer once is meanwhile prevented by allowing the excess liquid to fiow Specification of Letters Patent. Patented Aug. 241:, 1915, Application filed May 5, 1915. Serial No, 25,995. I

out of the vessel without varying the pres sure therein.

To secure the mo st eflicient impregnation it is often times desirable to vary the pressure within the vessel so as to produce a surging action of the liquid within its pores 1 and interstices, thereby partially expelling some of the liquid and air which have previously been introduced, and then injecting an additional amount thereinto.

The alternate inflow of liquid and air may be more positivelysecured in some cases by subjecting the article to continuously increasing air pressure and introducing the liquid intermittently, so as to produce a succession of definite films.

Having thus described my invention, what I claimand desire to secure by Letters Patent is:

1. The method, which consists in first subjecting wood and other porous material to a "acuum, and then forcing thereinto commingled liquid and air.

2. The methodof impregnating wood and I is forced into the pores, voids and interstices of the article in advance of, and commingled with, the air, then cutting off the inflow of fluid, then reducing said pressure and drawing ofi said liquid'under such reduced pressure.

3. The method of impregnating wood and other porous material with a liquid, which consists inconfining the article in a hermetically sealed vessel, then subjecting the article to a vacuum, then drenching the article with the liquid to form a covering film, and meanwhile subjecting said film to increasing air pressure whereby the liquid of said film is forced into the pores, voids and interstices of the article in advance of, and commingled with, the air. r

4. The method of impregnating wood and other porous material with a liquid, which consists in confining the article in a hermetically sealed vessel, then subjecting the article to a vacuum, then drenching the article with the liquid to form a covering film, and meanwhile subjecting said film to increasing air pressure whereby the liquid of said film is forced into the pores, voids and interstices of the article in advance of, and commingled with, the air, and then gradually permitting the accumulated liquid to submerge the articles and increasing the pressure.

5. The method of impregnating wood and other porous material with .a liquid, which consists in confining the article in a her metically sealed vessel, then subjecting the article to a vacuum, then continuously drenching the article with the liquid to form a covering film, and meanwhile subjecting said film to gradually increasing and varied air pressure, then cutting oil the inflow of fluid, then reducing the pressure and drawing off the free liquid under such reduced pressure.

6. The method of impregnating wood and other porous material with a liquid, which consists-in confining the article in a hermetically sealed vessel, then subjecting the article to a vacuum, then continuously drenching the article with the liquid to form successive covering films, and meanwhile subjecting said article to continuously increasing air pressure until the requisite amount of commingled liquid and 'air has been introduced into the article, then reducing said pressure and draining off the free liquid under such reduced pressure.

7. The method which consists in subjecting a porous article to a vacuum and then covering it with a flowing film of liquid and meanwhile subjecting it to increasing air pressure.

8. The method which consists in subjecting a porous article to a vacuum and then drenching it with liquid in the presence of air under progressively increasing pressure.

9. The method which consists in subjecting a porous article to a vacuum, then drenching it continuously with a liquid and meanwhile applying to it progressively increasing air pressure.

10. The method which consists in subject- .ing a porous article in a hermetically sealed vessel to a vacuum, then covering it with a continuously flowing film of liquid, and meanwhile subjecting it to progressively increasing air pressure, then cutting off the inflow of fluid, reducing the air pressure, and drawing of]? the surplus liquid under such reduced air pressure.

11. The method of impregnating Wood and other porous material with a liquid, which consists in confining the article in a hermetically sealed vessel, then subjecting the article to a vacuum, then drenching the article with the liquid to form a covering film and meanwhile subjecting said film to increasing air pressure whereby the liquid of said film is forced into the pores, voids and interstices of the article in advance of, and commingled with, the air, then gradu ally permitting the accumulated liquid to submerge the article and increasing the pressure, then cutting off the inflow of liquid, reducing the pressure and drawing off the free liquid under such reduced pressure.

12. The method of impregnating wood and other porous material with a liquid which consists in confining the material in a hermetically sealed vessel, then subjecting the material to a vacuum, then continuously drenching the article with the liquid to form a covering film, meanwhile subjecting said film to increasing air pressure and permitting the accumulated liquid in the vessel to flow out of the vessel to prevent submergence of the material until the desired amount of commingled liquid and air has been injected into the article, then shutting off the outflow of liquid from the vessel to permit complete sub'mergence of the material without increase of pressure and then increasing the pressure to the desired limit.

13. The method of impregnating wood and other porous material with a liquid which consists in confining the material in a hermetically sealed vessel, then subjecting the material to a vacuum, then continuously drenching the article with the liquid to form a covering film, meanwhile subjecting said film to increasing air pressure and permitting the accumulated liquid in the vessel to flow out of the vessel to prevent submergence of the material until the desired amount of commingled liquid and air has been injected into the article, then shutting off the outflow of liquid from the vessel to permit complete submergence of the material without increase of pressure and then increasing the pressure to the desired limit, then cutting off the inflow of liquid, reducing the pressure and drawing off the free liquid under such reduced pressure.

Signed at New York, county'and State of New York, this 3rd day of May, 1915.

HENRY S. LOUD.

Witness:

T. D. MERWIN. 

